Propagation of Sound in a Shallow Bay

Acoustic pressures and particle velocities were measured at several distances from both pulsed multipole and continuous monopole broad‐band sound sources, in a shallow bay. Pressure attenuation was less for pulsed than for continuous signals in the range of 80 to 640 Hz. Relationships of particle velocity to pressure amplitudes were determined, using a reference level common to both. The ratios of these parameters were found to remain constant for all distances beyond 1 m from the sources for frequencies from 20 to 640 Hz. These ratios were also valid for ambient noise measured at this location. Particle motion appeared to be primarily vertical and to attenuate at the same rate as pressure once this ratio bad been attained. Shallow‐water marine organisms may thus receive nearfield stimuli at relatively great distances from sources.